Facing a chorus of calls for his resignation, Attorney General Eric Holder is readying for a session of pointed inquiries and probable political bombast as he heads to Capitol Hill Thursday to answer more questions about the Justice Department's involvement in a botched border gun interdiction program known as “Fast and Furious.”

Fast and Furious was created by a regional ATF office in Arizona in 2009 to allow US officials to follow gun smuggling trails in order to ensnare not just smugglers, but also major cartel bosses. But US authorities instead lost track of more than 2,000 guns bought from US gun shops by cartel straw buyers – weapons that since have been traced to at least 300 murder scenes in Mexico and linked to the deaths of two US agents, border patrol agent Brian Terry and Jaime Zapata, an attache with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) working out of Mexico City.

The Bronx-born Mr. Holder, a former Reagan judicial appointee, has repeatedly angered conservatives, gun rights activists, and tea party adherents for, among other things, proposing to put terrorists on trial in civilian courts, including in New York, his alleged mishandling of the prosecution of the New Black Panther party for alleged voting-booth thuggery, and refusing to investigate ACORN, the community activist group.

Holder has steadfastly denied that he knew about the details of Fast and Furious, even as the botched operation has slowly built into the biggest test yet of his political survival skills. A steady stream of Fast and Furious revelations has turned the Holder Justice Department into a symbol, to some, of the failures of the Obama administration.

On Wednesday, more questions emerged about the role of Assistant Attorney General Lanny Breuer, one of Holder's top deputies, and whether Mr. Breuer knowingly misled Congress when he allegedly signed off on a draft of a May 2 letter stating that allegations that the ATF had lost track of any guns were “false.” The department recanted that letter last week, citing “inaccuracies,” and also apologized to congressional staffers for one official calling them, in a note, “stooges for the gun lobby.”

Those missteps and walk-backs, added to the Justice Department's reluctance to voluntarily allow key employees to talk to congressional investigators, have only fueled conspiracy theories among gun owners. Chief among them: Fast and Furious was an Obama administration ploy to goose border violence in order to propose more gun control legislation under the guise of curtailing the flow of arms from north to south.

“Public outrage comes from average Americans who cannot understand why their very own government would intentionally allow criminals to illegally buy weapons for trafficking into Mexico,” Sen. Charles Grassley (R) of Iowa told the Senate Wednesday as he called for Breuer's resignation.

No evidence has emerged tying Holder directly to Fast and Furious. While Holder has criticized the program and vowed that it would never happen again, he also recently took a shot at what he clearly perceives as the political underpinnings of the mounting attacks on his leadership.

"I have ultimate responsibility for that which happens in the department, but I cannot be expected to know the details for every operation that is ongoing in the Justice Department on a day-to-day basis," Holder told Congress last month. “Equally [as] unacceptable [as Fast and Furious], however, is the fact that too many in Congress are opposed to any discussion of fixing loopholes in our laws that facilitate the staggering flow of guns each year across our border to the south." It "seems clear that some in Congress are more interested in using this regrettable incident to score political points than in addressing the underlying problem," Holder said.

In a sign that the Fast and Furious furor is getting under his skin, Holder last week lambasted a reporter for the Daily Caller, a conservative Internet publication that has been zealously covering the scandal, telling him, “You guys need to – you need to stop this. It’s not an organic thing that’s just happening. You guys are behind it.”

While the White House has remained relatively quiet on Fast and Furious, other Democrats have come to Holder's defense, saying Republican calls for resignation are clearly partisan, in part because they've largely ignored a smaller-scale gun-walking program, “Operation Wide Receiver,” implemented during the Bush administration. However, that program, unlike Fast and Furious, was a joint operation with Mexican authorities.

“Holder has a history of dedication to the rule of law with little regard for partisan politics,” blogger Britton Loftin wrote on the opinion site, Politic365. “His ability to continue the work of chief lawyer for the United States in the face of intense political posturing shows that it is not likely the nation’s first African-American Attorney General is going anywhere any time soon."

Unlike the 52 Republican congressmen, two GOP senators, the bulk of presidential candidates, and two sitting governors who have asked Holder to resign, Seantor Grassley and Rep. Darrell Issa (R) of California, who is conducting an investigation as head of the House oversight committee, have stopped short of asking him to do so.

“The fact is it is not about any one person. It is not about Eric Holder, it is not about [Breuer],” whose office signed off on the wiretaps for the operation, Representative Issa told reporters at a recent Monitor breakfast event. Instead, “it is about a failure that seems to be pervasive within [the Department of] Justice that investigations play fast and loose with the expectations of what is right or wrong when it comes to ... collateral damage. This isn’t the first time the FBI and other agencies have been involved in investigations in which bad people are allowed to continue doing bad things in the name of going after bad people.”

But after Grassley's call on Wednesday for Breuer to resign, Issa is expected to demand at Thursday's hearing that Holder “clean house” at the Justice Department.